Decimal to Binary

Question

I have a number that I would like to convert to binary (from decimal) in C.

I would like my binary to always be in 5 bits (the decimal will never exceed 31). I alrea

Answer 1

My take:

char* to_bitstring(uint32_t val, char buffer[], int size) {
    buffer[--size] = 0;
    while (size > 0) {
        buffer[--size] = (val % 2 ? '1' : '0');
        val = val >> 1;
    }

    return buffer; /* convenience */
}

This will write SIZE characters to BUFFER:

char buffer[17];
printf("%s\n", to_bitstring(42, buffer, sizeof(buffer)));

And will print:

0000000000101010